聚焦离子束(focused Ion beam,FIB)作为一种用于金刚石微铣刀的特种加工方式,其引发的损伤程度直接关联到刀具的加工性能和寿命。课题组采用LAMMPS软件进行分子动力学(Molecular Dynamics,MD)模拟,结合SRIM软件的分析结果,探究单晶金刚...聚焦离子束(focused Ion beam,FIB)作为一种用于金刚石微铣刀的特种加工方式,其引发的损伤程度直接关联到刀具的加工性能和寿命。课题组采用LAMMPS软件进行分子动力学(Molecular Dynamics,MD)模拟,结合SRIM软件的分析结果,探究单晶金刚石亚表层损伤的形成机理和入射离子能量对损伤深度和范围的影响。模拟结果表明:随着入射离子能量的提升,离子束在材料内的渗透深度及引起的非晶层和点缺陷损伤均有所增加;进一步的研究发现损伤形成过程中材料局部温度的上升可能诱发自退火现象,且与离子入射能量成正比,该现象对于理解聚焦离子束加工引起的损伤有着至关重要的意义;而势能的变化与损伤形成之间的显著对应关系揭示了第一邻近原子的势能明显高于第二邻近原子,进而高于Other类型原子,这一发现有助于深入理解损伤形成的微观过程。因此,精确控制入射能量是实现金刚石材料高精度聚焦离子束加工的关键,且对自退火效应和势能变化的研究对损伤监控与控制同样重要。展开更多
Background and Objectives: The indication for treatment in HBsAg-positive patients with low viral load and normal transaminases requires an assessment of fibrosis. In resource-limited settings, free hepatic fibrosis e...Background and Objectives: The indication for treatment in HBsAg-positive patients with low viral load and normal transaminases requires an assessment of fibrosis. In resource-limited settings, free hepatic fibrosis evaluation tests can aid in therapeutic decision-making. Our study aims to demonstrate the utility of assessing hepatic fibrosis using non-invasive markers (APRI and FIB-4) in patients with chronic B viral hepatitis without cytolytic activity and low viral replication in our context. Patients and Methods: This is a retrospective cross-sectional study conducted between January 2018 and December 2021 at the University Hospital Center of Bouaké. Included were all patients aged ≥18 with normal transaminases (Results: Our study included 241 patients, with a mean age of 36.19 years (±10.52 years) and a male predominance of 52%. The mean FibroScan<sup>®</sup> value was 6.44 ± 2.3 kPa, and 68 patients (28.22%) had fibrosis >7 kPa. To exclude significant fibrosis (FS Conclusion: A significant proportion of HBV-infected patients with normal ALT and low viral load have active liver disease. Both FIB-4 and APRI biological scores are useful in identifying individuals without significant fibrosis with a good negative predictive value (>50%).展开更多
Hepatitis C infection in people living with Human Immunodeficiency Virus (HIV) poses management challenges. Of the world’s population, 3% are estimated to have chronic Hepatitis C Virus (HCV) infection, which is resp...Hepatitis C infection in people living with Human Immunodeficiency Virus (HIV) poses management challenges. Of the world’s population, 3% are estimated to have chronic Hepatitis C Virus (HCV) infection, which is responsible for about 70% of cases of chronic hepatitis (accelerated chronicity in the presence of HIV and for such major complications as cirrhosis and hepatocellular carcinoma. The fibrosis 4 (FIB-4) and Aspartate aminotransferase/platelet ratio index (APRI) scores are simple, inexpensive tests accessible to most people, and their performance has not yet been studied in C?te d’Ivoire. Objective: To prospectively evaluate the diagnostic performance of APRI and FIB-4 scores in liver damage in those co-infected with HIV/HCV in C?te d’Ivoire. Methods: This study was conducted over three months. The patients came from national blood transfusion center of the cities of Man and Daloa. The criteria for selecting respondents were at least 18 years of age and a positive test for HIV and HCV. APRI and FIB-4 scores were calculated for each patient from biological data obtained by COBAS C311 (Roche Hitachi, Japan). Statistical analyses were performed using GraphPad and MED-CALC software. Results: Our study involved 30 patients (men) of middle age (25 - 52 years), with extremes ranging from 0.67 to 8 for APRI and 0.201 to 22 for FIB-4. A predictive APRI and FIB4 score of significant hepatic fibrosis was observed in 23% of patients;however, 46% and 54% of patients for the APRI and FIB-4 score, respectively, would not have significant fibrosis. An APRI and FIB4 score not included in the classification limits of the type of fibrosis hepatitis was observed in 31% and 23% of patients, respectively. Conclusion: The performance of the APRI and FIB-4 biological scores analyzed according to the interpretation of their cut-off values would enable classifying about 70% and 77%, respectively, of the patient population in the stages of hepatitis C fibrosis.展开更多
文摘聚焦离子束(focused Ion beam,FIB)作为一种用于金刚石微铣刀的特种加工方式,其引发的损伤程度直接关联到刀具的加工性能和寿命。课题组采用LAMMPS软件进行分子动力学(Molecular Dynamics,MD)模拟,结合SRIM软件的分析结果,探究单晶金刚石亚表层损伤的形成机理和入射离子能量对损伤深度和范围的影响。模拟结果表明:随着入射离子能量的提升,离子束在材料内的渗透深度及引起的非晶层和点缺陷损伤均有所增加;进一步的研究发现损伤形成过程中材料局部温度的上升可能诱发自退火现象,且与离子入射能量成正比,该现象对于理解聚焦离子束加工引起的损伤有着至关重要的意义;而势能的变化与损伤形成之间的显著对应关系揭示了第一邻近原子的势能明显高于第二邻近原子,进而高于Other类型原子,这一发现有助于深入理解损伤形成的微观过程。因此,精确控制入射能量是实现金刚石材料高精度聚焦离子束加工的关键,且对自退火效应和势能变化的研究对损伤监控与控制同样重要。
文摘Background and Objectives: The indication for treatment in HBsAg-positive patients with low viral load and normal transaminases requires an assessment of fibrosis. In resource-limited settings, free hepatic fibrosis evaluation tests can aid in therapeutic decision-making. Our study aims to demonstrate the utility of assessing hepatic fibrosis using non-invasive markers (APRI and FIB-4) in patients with chronic B viral hepatitis without cytolytic activity and low viral replication in our context. Patients and Methods: This is a retrospective cross-sectional study conducted between January 2018 and December 2021 at the University Hospital Center of Bouaké. Included were all patients aged ≥18 with normal transaminases (Results: Our study included 241 patients, with a mean age of 36.19 years (±10.52 years) and a male predominance of 52%. The mean FibroScan<sup>®</sup> value was 6.44 ± 2.3 kPa, and 68 patients (28.22%) had fibrosis >7 kPa. To exclude significant fibrosis (FS Conclusion: A significant proportion of HBV-infected patients with normal ALT and low viral load have active liver disease. Both FIB-4 and APRI biological scores are useful in identifying individuals without significant fibrosis with a good negative predictive value (>50%).
文摘Hepatitis C infection in people living with Human Immunodeficiency Virus (HIV) poses management challenges. Of the world’s population, 3% are estimated to have chronic Hepatitis C Virus (HCV) infection, which is responsible for about 70% of cases of chronic hepatitis (accelerated chronicity in the presence of HIV and for such major complications as cirrhosis and hepatocellular carcinoma. The fibrosis 4 (FIB-4) and Aspartate aminotransferase/platelet ratio index (APRI) scores are simple, inexpensive tests accessible to most people, and their performance has not yet been studied in C?te d’Ivoire. Objective: To prospectively evaluate the diagnostic performance of APRI and FIB-4 scores in liver damage in those co-infected with HIV/HCV in C?te d’Ivoire. Methods: This study was conducted over three months. The patients came from national blood transfusion center of the cities of Man and Daloa. The criteria for selecting respondents were at least 18 years of age and a positive test for HIV and HCV. APRI and FIB-4 scores were calculated for each patient from biological data obtained by COBAS C311 (Roche Hitachi, Japan). Statistical analyses were performed using GraphPad and MED-CALC software. Results: Our study involved 30 patients (men) of middle age (25 - 52 years), with extremes ranging from 0.67 to 8 for APRI and 0.201 to 22 for FIB-4. A predictive APRI and FIB4 score of significant hepatic fibrosis was observed in 23% of patients;however, 46% and 54% of patients for the APRI and FIB-4 score, respectively, would not have significant fibrosis. An APRI and FIB4 score not included in the classification limits of the type of fibrosis hepatitis was observed in 31% and 23% of patients, respectively. Conclusion: The performance of the APRI and FIB-4 biological scores analyzed according to the interpretation of their cut-off values would enable classifying about 70% and 77%, respectively, of the patient population in the stages of hepatitis C fibrosis.